Garrett's Acropolis

General

My system is around 1200 gallons. The main glass display/growing tank is approximately 600 gallons and measures 240" x 49" x 14" deep. The next tank is a refugium that holds about 90 gallons and is made of high-density polyethylene. There are also two 300 gallon sumps made of fiberglass. The stand consists of 12 redwood legs. They meet with over 180 pounds of extruded aluminum beams that make up the flat surface for the glass tank to sit on. There is a ¾" layer of baltic birch plywood separating the aluminum from the glass tank.

Circulation

The main pumps are two alternating Sweetwater high-efficiency pumps. These create flow in the tank by pushing through a 1 ½" mixing eductor. They also power two surge tanks that fill and release every ten minutes or so. Two smaller pumps that alternate in sequence with the main pumps boost the flow on the far end of the tank. I also installed an EcoTech Marine VorTech MP40 pointing upward in the middle of one end of the tank to create swells. The remainder of the flow comes from an excited Vlamingi Tang that darts around the system.

Controllers

The temperature is controlled by an Aqua Logic Dual-Stage Temperature Controller. For heating, the controller turns on a pump that operates in a closed-loop of fresh water. The fresh water is taken from a 5 gallon cooler box and is pushed through a standard 30 gallon gas water heater. From there, it runs through about 100' of thin wall PVC located in the last 300 gallon sump and then back to the cooler box. For cooling, I only use blower-type fans that are directed at the surface of the water in the main system. If it is an exceptionally hot and humid day, I will add another fan to blow on the sump. I have the temperature set to 77° +/- 1° in wintertime and 78° +/- 1° in the summer.

Filtration

I try to use natural methods of filtration as much as possible. There are no filter socks or mechanical filters of any kind on this system. I use 4" to 6" of aragonite sand as a deep sand bed in the refugium and one of the 300 gallon sumps. There is approximately 1200lbs. of base rock that was seeded to become live rock in the refugium and sump. The live rock in the sump is arranged to form several vertical walls that the water must flow through; sponges and other filters here catch the suspended particles naturally to clarify the water. I also use a massive Euro-Reef protein skimmer that can run on up to 7Eheim pumps, although normally it runs on 5. The skimmer is fed by a 2" overflow pipe in the main tank.

Lighting

Sunlight is filtered through blue plastic and various levels of shade cloth depending on the time of year. I also have a pair of150 watt double-ended lights on a light mover over a 4-foot section on one end of the tank. This is great for seeing phosphorescent pigments and is used as supplemental lighting for corals that look best under 20K lighting. The light is only on during the day and the duration varies depending on the time of year.

System Parameters and Water Testing

I test the alkalinity every other day with a Salifert test kit. I try to be between 8dKH and 10dKH. For salinity, I aim for 35ppt and test once per week using a mid- to high-end refractometer. I do a phosphate test once per week using a Hanna low range phosphate meter. I also mail a water sample every few months or so to Aquarium Water Testing to get a second opinion as well as see other values that are difficult to test for using hobbyist-level test kits. Here are the results for May 23, 2011:

Since the copper rating came back high, I change out the activiated carbon and that solved the problem. Generally things like this—buildups of impurity occuring, probably from one of the additives—that cause mysterious problems with corals and inverts.

My system uses a large calcium reactor to replace calcium and alkalinity. There are certain times during the year that the demand for alkalinity can reach 2.6dKH of usage in a 24-hour period. At this rate, the calcium reactor cannot keep up and calcium and alkalinity supplementation becomes necessary. Due to the large calcium reactor, my system always has a pH on the lower side, varying from a low of 7.85 up to 8.15 at the peak of the day.

I use Granular Ferric Oxide to remove phosphates and some carbon in a reactor. This seems like the most stable way to safely export/bind phosphate in this system with low fish bio-load. I try to keep phosphate levels between .00 and .04ppm. I replace the media if it reaches .05ppm.

Maintenance Schedule

I go through about 100 gallons or so of Tropic Marine Pro Reef Sea Salt each month. All in all, I don't really need to focus on water changes since I am testing my water and supplementing when necessary. Nutrients are being consumed by the system so nitrate and phosphate do not build up. I use a Reverse Osmosis/Deionization unit for top-off as well as to mix up any new batches of saltwater.

Livestock

Fish
I have a 14" Vlamingi Tang, a Blue Eye Colie Tang, 4 Yellow Tangs, a Brown Tang, a Hippo Tang, some Six Line Wrasses, a pair of mis-bar Clownfish in the refugium and several fat target Mandarin fish.

Corals
Mainly SPS corals like Acropora, Montipora and Pocillopora, I would estimate that I have at least 200 types. I love to collect all types of small polyp stony corals.